The Santa Clara County Vector Control District (SCCVCD) has confirmed three dead American Crows have tested positive for West Nile Virus (WNV) in the South Bay. The birds were found on May 7 in Monte Sereno (zip 95030), on May 10 in Los Altos (zip 94022) and on May 13 at Bollinger Road and Johnson Avenue in San Jose (zip 95129).

Dead birds are an early warning system for West Nile Virus. A bird testing positive for WNV alerts health officials the virus is present in an area. Transmitted by mosquito bites, WNV causes mild to severe flu-like symptoms such as fever, headache, body-ache and, in severe cases, significant neurological symptoms or even death. The elderly and those with weak immune systems are most susceptible. In 2009, California reported 129 WNV infections, with 112 symptomatic cases and four fatalities.

No human cases or WNV-positive mosquitoes have been found in Santa Clara County this year. SCCVCD continues to collect adult mosquitoes weekly throughout the county for testing.

The SCCVCD asks the county's residents to report crows, jays, sparrows, finches, birds of prey or tree squirrels that have been dead for less than 48 hours and do not appear to have died because of an injury. They should contact the State of California WNV hotline at 877-WNV-BIRD (2473) or online at www.westnile.ca.gov

Heavy rainfall this season means mosquito abatement remains the key to preventing West Nile Virus. Consequently, SCCVCD has heightened its mosquito surveillance and outreach programs. Residents are asked to eliminate standing water on their properties to help eliminate mosquito breeding sources. A single, poorly maintained pool in the backyard can produce millions of mosquitoes.

For assistance on mosquito control and WNV, contact Santa Clara County Vector Control District on (408) 918-4770 / (800) 675-1155 or visit www.sccvector.org.